Brake lining and method of making same



lPatented Sept. 24, 1929 STATES ATEl" @FFlCE FREDERICK C. STANLEY, FFAIEFIELD, CONNECTICUT, ASSIGNOR TO THE RAYBESTOQ COMPANY, 0F

BRIDGEPORT, CONNECTICUT, A CORPORATION OF CONNECTICUT IBRAKE LINING- ANDME'JZHOD OF MAKING SAME N0 Drawing.

This invention relates to brake lining as generally applied toautomobile brakes and the process of a particular object the productionof a lining which will not freeze to the brake drum when wet and whichretains its high coefficient of friction for braking purposes. At thepresent time considerable trouble is experienced, and also considerabledamage is done, by entrance of moisture into the brake or brake band andlater freezing in cold weather when the car is left standing with thebrakes applied, so that the band or lining freezes to the metal drum; Itis then, of course, impossible to start the car without first releasingthe band from the drum, or, if an attempt is made to start the car, "therear axle or other mechanism may be brpken. Numerous attempts have beenmade to overcome this difliculty but witholut success until the presenttime. I have found that by treating the brake band with a solutioncontaining sufiicient glycerin that it will be retained in such aquantity by the band as to leave by its contact an enduring film ofglycerin on the surface of the brake drum, it will diminish the force ofadhesion between ice and the drum and the band will not freeze to thedrum. Glycerin will mix with water in almost any proportion and themixtures of glycerin and water have a lower freezing temperature than 32F. or the normal freezing temperature of water, and the greater theproportion of glycerin in the mixture the lower will be the freezingpoint. This thin film of glycerin adjacent the surface 0 the drum mixeswith the moisture should any enter the brake and forms a film next tothe surface of the drum which has a Very low freezing point, andtherefore, the band cannot freeze to the drum in temperatures which areordinarily encountered in most climates.

In actual practice asbestos brake lining has been immersed for from oneto five minutes in a mixture of glycerin and water in variousproportions from E glycerin and 87 70 water to 50% glycerin and 50%water, and then after pouring water through the brakes the brake hasbeen subjected to a temperature of 5 below zero for an hour, and in allcases the band did not freeze to the drum but easily its.

making the same, and has as friction,

it increases the efficiency of the brakes.

freed itself when Application and August so, 1926. Serial no; 132,655.

the brake was released, al-

though the lining treated with the solution having the higher proportionof glycerin was freed somewhat more readily than the lining treated withthe lower proportions of glycerin. I am, therefore, uncertain as to theexact limits for the relative proportions of glycerln,

but it is believed that practically all proportions would have somefreeing effect depending somewhat on the temperatures in which thebrakes the larger amount of are to be used. However, glycerin ispreferable enters the brake some of be washed away and some of theglycerin may be lost in severe use of the brake.

In applying the or lining, it may be applied to the brake band glycerinto the fibre or yarn or untreated tape or sheet from which the lining ismade,

completed lining, a sutficient length and the material is treated oftime to cause some penetration of the glycerin into the lining, althoughit is not necessary that there be a complete impregnation or saturation.glycerin may also with the saturant he be applied by mixing it hinder orcompound with which the fibres of the lining are treated in themanufacture of the lining.

It is believed that from about 1% to about 10% of glycerin in thesaturant or compound are the proportions which would give the desiredresults, al-

though of course,

to these proportions. f cation and claims the term I do not wish to belimited Thoughout the specifiimpregnated does not necessarily meanscompletely saturated.

The effect is secured because of the peculiar properties of glycerin. lnthe first place the glycerin in small quantities does not decrease theefficienoy of the brakes.

in other words it does not decrease the coeflicient of end, it cannot beand tests even seem to indicatethat Sec- .vaporized by the temperaturesordinarily induced by use of the brake.

Third, its

freezing or congealing temperature having a freezing temperature belowthe noror it may be applied to the mal freezing temperature of water,and therefore, by its use we always have a film of a, lower melting anda lower freezing temperature between the band and the'drum. That is,

5 glycerin has the peculiar property that in small quantities or in athin film it does not decrease the efficiency of the brake, and it formsa mixture with water having a low freezing point.

Having thus set forth the nature of my invention, what I claim is:

1. A brake lining comprising an impregnated fibre body treated withglycerin.

2. A brake lining composed of a suitable fibre impregnated with asaturant containing glycerin.

3. A brake lining comprising asbestos fibre and treated with glycerin.

4. The process of preventing freezing of a fibre brake lining to itsdrum in cold weather which consists in treating the fibre with a liquidcontaining glycerin a sufficient time to cause some penetration'of thefibre by the glycerin.

5. A brake lining comprising a fibre tape treated with glycerine.

6. A brake lining composed of a tape comprising asbestos fibre andtreated with glycerine to cause some penetration of the fibre by theglycerine.

In testimony whereof I aflix my signature.

FREDERICK G. STANLEY.

